#include "stdio.h"

int main(){
    char a[]="I am a boy.",b[20],*p1,*p2;
    p1=a;
    p2=b;
    while(*p1!='\0'){
        *p2=*p1;
        p1++;
        p2++;
    }
    *p2='\0';
    printf("string a is:%s\n",a);
    printf("string b is:%s\n",b);
    return 0;
}